Arc lamp mounting structure

ABSTRACT

A mounting structure in which an arc lamp is positioned without inducing stresses in the lamp during high-loading environments. The lamp has a spherical ferrule placed around each end. One spherical ferrule is then clamped tightly between a recessed surface in one end of the mounting structure and a pressure plate having a like recessed surface. The pressure plate is firmly tightened on the one spherical ferrule in a perpendicular direction relative to the lamp by a plurality of clamping screws connected to the one end of the mounting structure. The other spherical ferrule fits into a cylindrically bored hole of the other end of the mounting structure and is restricted to movement in only the axial direction. A spring-loaded collet is positioned in a counter bore of the cylindrically bored hole and is compressed against the other spherical ferrule. A retaining plate having a circular opening in which the collet can move axially holds the spring in compression against the collet by a plurality of retaining screws. The retaining screws secure the retaining plate to the other end of the mounting structure for allowing axial movement of the collet through the circular opening of the retaining plate.

United States Patent [72] Inventor Emil A. Mosser, Jr.

Newport Beach, Calif. [211 App]. No. 815,431 [22] Filed Apr. 11, 1969 [45] Patented Aug. 10, I971 [73] Assignee The United States of America as represented by the Secretary of the Army [54] ARC LAMP MOUNTING STRUCTURE 1 Claim, 1 Drawing Fig.

52 us. CL 240/41 A, 240/11.4 R, 240/52 R, 339/52 S, 339/55 [51] lnLCl. F21v2l/00 [50] Field of Search 240]! 1.4, 41, 41A, 52; 339/52, '55

[56] References Cited UNITED STATES PATENTS 2,791,679 5/1957 l-lierholzer, Jr. et a1. 339/52 X 2,997,574 8/1961 Miskella 240]] 1.4 3,095,155 6/1963 Schleifer 240/1 1.4 X 3,141,719 7/1964 Moore 240/11.4X 3,351,884 11/1967 Pistey 339/52 FOREIGN PATENTS 689,690 9/1930 France 339/55 Primary Examiner- Samuel S. Matthews Assistant Examiner-Richard M. Sheer Atlorneys- Harry M. Saragovitz, Edward J. Kelly, Herbert Eerl and James T Deaton ABSTRACT: A mounting structure in which an arc lamp is positioned without inducing stresses in the lamp during highloading environments. The lamp has a spherical ferrule placed around each end. One spherical ferrule is then clamped tightly between a recessed surface in one end of the mounting structure and a pressure plate having a like recessed surface. The pressure plate is firmly tightened on the one spherical ferrule in a perpendicular direction relative to the lamp by a plurality of clamping screws connected to the one end of the mounting structure. The other spherical ferrule fits into a cylindrically bored hole of the other end of the mounting structure and is restricted to movement in only the axial direction. A springloaded collet is positioned in a counter bore of the cylindrically bored hole and is compressed against the other spherical ferrule. A retaining plate having a circular opening in which the collet can move axially holds the spring in compression against the collet by a plurality of retaining screws. The retaining screws secure the retaining plate to the other end of the mounting structure for allowing axial movement of the collet through the circular opening of the retaining plate.

PATENTEDAUBIOIHYI v 5 3 Emil A. Mosser, Jr.

INVENTOR BY yjix ARC LAMP MOUNTING STRUCTURE BACKGROUND or THEINVENTION This invention is in the field of arc lamp transmission methods and specifically to a novel mounting structure for allowing heavy loading without perpendicular motion and yet allowing axial motion. A problem of previous lamp-mounting methods under heavy loading conditions was a tendency for the lamp to move in a perpendicular direction to its axis. Some of these prior art mounting structures induced bending or compressional stresses in the lamp. Cylindrical ferrules have been tried in mounting structures, and it was found that the lamps become misaligned with the other optical elements in the transmission system.

SUMMARY OF THE INVENTION This invention relates to an improved lamp-mounting structure for use in optical transmission systems. An important feature of this invention is in the use of spherical ferrules for providing axial movement of the lamp without the undesirable perpendicular movement. A mounting structure in the general shape of a C is used with the lamp being firmly attached at one end and being connected for axial movement without any perendicular movement at the other end of the mounting structure. One spherical ferrule is clamped tightly between a recessed surface in one end of the mounting structure and a pressure plate having a like recessed surface. The pressure plate is firmly tightened on the one spherical ferrule in a perpendicular direction relative to the lamp by a plurality of clamping screws. The other spherical ferrule fits into a cylindrically bored hole at the other end of the mounting structure. A spring-loaded collet is positioned in a counterbore of the cylindrically bored hole and is compressed against the other spherical ferrule by the spring being held in compression by a retaining plate. The other spherical ferrule is prevented by the collet from moving in the perpendicular direction. A circular opening in the retaining plate allows a small end of the collet to move axially therethrough, thus allowing axial movement of the other spherical ferrule and the arc lamp under high-loading environments.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is an embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the preferred embodiment, an arc lamp 12 is shown mounted on a mounting structure having the general shape of a C. One spherical ferrule 14 is clamped into one end 8 of the mounting structure and the other spherical ferrule 16 is clamped into the other end 9 of the mounting structure. One end 8 of the mounting structure includes a pressure plate 30 that is tightened down on spherical ferrule 14 by-a plurality of clamping screws 22 (only one of which is shown). A recessed portion of pressure plate 30 and the one end 8 of the mounting structure have beveled edges 2, 3, 4 and 5 that fit tightly against spherical ferrule 14, holding the lamp to the one end of mounting structure.

The other end 9 of the mounting structure includes a cylindrically bored hole and'a counterbore portion of the cylindrically bored hole. Another spherical ferrule 16 fits into the cylindrically bored hole and is restricted to movement only in the axial direction. A circular collet 18 is positioned in the counterbore and is in contact with the other spherical ferrule at bevel edge 6 that runs entirely around the collet. A helical spring 20 is positioned in the counterbore and biases bevel edge 6 of circular collet 18 against the other spherical ferrule 16 when retaining plate 24 is in position against the other end 9 of the mounting structure.

Since collet 18 can move axially in the other end 9 of the mounting structure, the distance between the ferrules need not be maintained to close tolerances, and differences in thermal expansion in the arc lamp 12 and mounting structure 10 do not cause axial stresses in the lamp.

Alignment of the arc lamp is an easy matter since the spherical fergu les always define one axis no matter where they are positioned and the spring-loaded collet relieves any need for accurate axial ferrule positioning. Heavy loads on the arc lamp is absorbed in the axial direction while shock movement in a direction perpendicular to the axis is suppressed, and thus preventing misalignment of the lamp.

While a specific embodiment of the invention has been shown and described, other embodiments may be obvious to one skilled in the art, in light of this disclosure. The invention should be limited in scope only be the following claims.

I. An arclamp-mounting structure comprising: a generally C-shaped member having opposite ends; an arc lamp having a first spherical ferrule surrounding one end of said lamp and a second spherical ferrule surrounding another end of said lamp; a pressure plate-clamping means at one end of said member for securing said first spherical ferrule therein, said pressure'plate and one end of said member having recessed portions and beveled corners thereon in their adjacent faces in which said first spherical ferrule is placed therein and clamped by a screw-fastening means; a retaining means at the other end of said member, said retaining means being shaped for receiving and slidably mounting said second spherical ferrule therein, said retaining means comprising: in said other end of said member, a cylindrically bored hole and a counterbore portion of said cylindrically bored hole; a helical spring, said helical spring positioned in said counterbore portion; a circular collet, said circular collet being surrounded by said helical spring and having a circular beveled inner portion at one end thereof, said second spherical ferrule fitting snugly against said circular beveled inner portion when said helical spring is compressed against said circular collet; and a retaining plate having a circular opening in its central portion; with said retaining plate being held securely by screw-fastening means to said other end of said member whereby said circular collet is axially movable parallel and along the axis of said lamp and within said circular opening of the retaining plate according to the degree of load transmitted from said other spherical ferrule through one end of said collet to said helical spring but is limited from moving radially by restriction of said helical 

1. An arc-lamp-mounting structure comprising: a generally Cshaped member having opposite ends; an arc lamp having a first spherical ferrule surrounding one end of said lamp and a second spherical ferrule surrounding another end of said lamp; a pressure plate-clamping means at one end of said member for securing said first spherical ferrule therein, said pressure plate and one end of said member having recessed portions and beveled corners thereon in their adjacent faces in which said first spherical ferrule is placed therein and clamped by a screwfastening means; a retaining means at the other end of said member, said retaining means being shaped for receiving and slidably mounting said second spherical ferrule therein, said retaining means comprising: in said other end of said member, a cylindrically bored hole and a counterbore portion of said cylindrically bored hole; a helical spring, said helical spring positioned in said counterbore portion; a circular collet, said circular collet being surrounded by said helical spring and having a circular beveled inner portion at one end thereof, said second spherical ferrule fitting snugly against said circular beveled inner portion when said helical spring is compressed against said circular collet; and a retaining plate having a circular opening in its central portion, with said retaining plate being held securely by screw-fastening means to said other end of said member whereby said circular collet is axially movable parallel and along the axis of said lamp and within said circular opening of the retaining plate according to the degree of load transmitted from said other spherical ferrule through one end of said collet to said helical spring but is limited from moving radially by restriction of said helical spring and circular collet on the side of said counterbore portion, said clamping means restricting both radial and axial movement of said first spherical ferrule therein and said retaining means restricting radial movement but allowing axial movement of said second spherical ferrule therein. 